U.S. patent application number 12/142934 was filed with the patent office on 2010-01-21 for method and apparatus for protecting scalable video coding contents.
This patent application is currently assigned to KOREAN BROADCASTING SYSTEM. Invention is credited to Sang Jin Hahm, Byung Sun Kim, Mun Churl Kim, Keun Sik Lee, Keun Soo Park.
Application Number | 20100014666 12/142934 |
Document ID | / |
Family ID | 41483936 |
Filed Date | 2010-01-21 |
United States Patent
Application |
20100014666 |
Kind Code |
A1 |
Park; Keun Soo ; et
al. |
January 21, 2010 |
Method and Apparatus for Protecting Scalable Video Coding
Contents
Abstract
Disclosed are a method and apparatus capable of reducing the
computational complexity of encryption and decryption by encrypting
only data of scalable video coding contents for each coding layer
in terms of temporal, spatial, and SNR scalabilities to provide a
service for protected scalable video coding contents, and capable
of protecting contents by generating and distributing an encryption
key for encryption and decryption depending on a class of a
contents consumer.
Inventors: |
Park; Keun Soo; (Seoul,
KR) ; Lee; Keun Sik; (Seoul, KR) ; Hahm; Sang
Jin; (Seoul, KR) ; Kim; Byung Sun;
(Gyeonggi-do, KR) ; Kim; Mun Churl; (Daejeon,
KR) |
Correspondence
Address: |
THE WEBB LAW FIRM, P.C.
700 KOPPERS BUILDING, 436 SEVENTH AVENUE
PITTSBURGH
PA
15219
US
|
Assignee: |
KOREAN BROADCASTING SYSTEM
Seoul
KR
ICU RESEARCH AND INDUSTRIAL COOPERATION GROUP
Daejeon
KR
|
Family ID: |
41483936 |
Appl. No.: |
12/142934 |
Filed: |
June 20, 2008 |
Current U.S.
Class: |
380/210 ;
380/279; 380/44; 717/178 |
Current CPC
Class: |
H04N 19/61 20141101;
H04N 19/70 20141101; H04N 21/2347 20130101; H04N 21/63345 20130101;
H04L 9/088 20130101; H04N 7/1675 20130101; H04N 21/234327 20130101;
H04L 2209/60 20130101; H04N 19/467 20141101; H04N 21/6582 20130101;
H04N 21/2662 20130101; H04N 19/34 20141101 |
Class at
Publication: |
380/210 ; 380/44;
717/178; 380/279 |
International
Class: |
H04N 7/167 20060101
H04N007/167; H04L 9/08 20060101 H04L009/08 |
Claims
1. A method for protecting scalable video contents in a scalable
video coding contents providing system that encrypts and provides
scalable video contents requested by a scalable video user
terminal, the method comprising: receiving the requested scalable
video contents; storing the received scalable video contents in a
scalable video contents archive and controlling to perform
authentication and generate an encryption key to be sent to the
user; performing the authentication and generating the encryption
key; imaging a scalable video in response to the request and coding
the imaged scalable video contents; encrypting the coded scalable
video contents using the generated encryption key; generating
encryption information metadata for the encrypted scalable video
coding contents; and transmitting the encrypted scalable video
coding contents and the generated encryption information metadata
to the scalable video user terminal via a network or a storage
medium.
2. The method of claim 1, wherein the encrypting comprises
selectively encrypting a disassembled low-pass filtered picture of
the lowest layer or a high-pass filtered picture of an upper layer
with respect to a temporally disassembled picture of an input video
of a base layer.
3. The method of claim 1, wherein the encrypting comprises
encrypting a base layer or an enhancement layer for coding data of
a Fine Granular Scalability (FGS) layer coded to have
Signal-to-Noise Ratio (SNR) scalability.
4. The method of claim 1, wherein the encryption information
metadata comprises an encryption parameter and an encryption
key.
5. A method for protecting scalable video coding contents in a
scalable video user terminal that decrypts and decodes encrypted
scalable video coding contents and encryption information metadata
received from a scalable video coding contents providing system,
the method comprising: parsing the received encryption information
metadata to obtain an encryption key and encryption information;
decrypting the received encrypted scalable video coding contents
using the encryption key and the encryption information; and
decoding and reproducing the decrypted scalable video contents.
6. The method of claim 5, wherein the encryption information
metadata comprises an encryption parameter and an encryption
key.
7. The method of claim 5, further comprising: when there is no
decryption tool in decrypting the received encrypted scalable video
coding content, acquiring, installing, and using the decryption
tool through a storage medium or a network.
8. The method of claim 5, further comprising: when there is no
encryption metadata for decryption in decrypting the received
encrypted scalable video coding content, requesting the encryption
metadata for decryption via a network, receiving and acquiring the
encryption metadata in response to the request, and using the
encryption metadata in decrypting the received encrypted scalable
video coding data.
9. A scalable video coding contents providing system for protecting
scalable video contents requested by a scalable video user
terminal, the system comprising: a user contents request
information receiving unit for receiving the requested scalable
video contents; a scalable video contents service control unit for
storing the received scalable video contents in a scalable video
contents archive and controlling to perform authentication and
generate an encryption key to be sent to a user; a user
authenticating and encryption key control unit for performing the
authentication and generating the encryption key; an imaging unit
for imaging a scalable video in response to the request; a scalable
video coding unit for coding the imaged scalable video contents; a
scalable video coding data encryption unit for encrypting the coded
scalable video contents using the generated encryption key; an
encryption information metadata generation unit for generating
encryption information metadata for the encrypted scalable video
coding contents; and an encrypted scalable video coding contents
and encryption information metadata transmission unit for
transmitting the encrypted scalable video coding contents and the
generated encryption information metadata to the scalable video
user terminal via a network.
10. The system of claim 9, wherein the scalable video coding data
encryption unit for encrypting the coded scalable video contents
using the generated encryption key encrypts the coding data of
temporal, spatial, and SNR scalability layers or encrypts a
combination of the temporal, spatial, and SNR scalability
layers.
11. The system of claim 10, wherein the scalable video coding data
encryption unit selectively encrypts a disassembled low-pass
filtered picture of the lowest layer or a high-pass filtered
picture of an upper layer with respect to a temporally disassembled
picture of an input video of a base layer.
12. The system of claim 10, wherein the scalable video coding data
encryption unit encrypts a base layer or an enhancement layer for
coding data of an FGS layer coded to have SNR scalability.
13. The system of claim 9, wherein the encryption information
metadata comprises an encryption parameter and an encryption
key.
14. A scalable video user terminal for protecting encrypted
scalable video coding contents and encryption information metadata
by decrypting and decoding the same, the terminal comprising: an
encrypted scalable video metadata parsing unit for parsing received
encryption information metadata to obtain an encryption key and
encryption information; a scalable encrypted video decryption unit
for decrypting the received encrypted scalable video coding
contents using the encryption key and encryption information; a
scalable video decoding unit for decoding the decrypted scalable
video contents; and a scalable decoded video rendering unit for
rendering and reproducing the decoded scalable video contents.
15. The terminal of claim 14, wherein the encryption information
metadata comprises an encryption parameter and an encryption
key.
16. The terminal of claim 14, wherein the scalable encrypted video
decryption unit acquires, installs, and uses a decryption tool
through a storage medium or a network when there is no decryption
tool in decrypting the received encrypted scalable video coding
contents.
17. The terminal of claim 14, wherein the scalable encrypted video
decryption unit requests the encryption metadata for decryption via
a storage medium or a network, receives and acquires the encryption
metadata in response to the request, and uses the encryption
metadata in decrypting the received encrypted scalable video coding
data when there is no encryption metadata for decryption in
decrypting the received encrypted scalable video coding
contents.
18. An apparatus for protecting scalable video coding contents, the
apparatus comprising: an input unit for dividing and inputting
input video data acquired in response to a request from a video
user terminal into at least one of temporal, spatial, and SNR
scalability layers; a coding unit for coding the input video data
of at least one of the temporal, spatial, and SNR scalability
layers; an encryption unit for encrypting video data of the coded
temporal, spatial, and SNR scalability layers; a generation unit
for generating metadata for the video data of the encrypted
temporal, spatial, and SNR scalability layers; and a storage unit
for combining and storing the encrypted coding data of the
temporal, spatial, and SNR scalability layers and the generated
metadata.
19. The apparatus of claim 18, wherein the encryption unit
selectively encrypts a disassembled low-pass filtered picture of
the lowest layer or a high-pass filtered picture of an upper layer
with respect to a temporally disassembled picture of an input video
of a base layer.
20. The apparatus of claim 18, wherein the encryption unit encrypts
a base layer or an enhancement layer for coding data of an FGS
layer coded to have SNR scalability.
21. The apparatus of claim 18, wherein the metadata comprises an
encryption parameter and an encryption key.
22. The apparatus of claim 18, wherein the encryption unit for
encrypting video data of the coded temporal, spatial, and SNR
scalability layers encrypts each of coding data of temporal,
spatial, and SNR scalability layers or any combination of the
temporal, spatial, and SNR scalability layers.
23. A method for protecting scalable video coding contents, the
method comprising: dividing and inputting input video data acquired
in response to a request from a video user terminal into at least
one of temporal, spatial, and SNR scalability layers; coding the
input video data of the at least one of the temporal, spatial, and
SNR scalability layers; encrypting the video data of the coded
temporal, spatial, and SNR scalability layers; generating metadata
for the video data of the encrypted temporal, spatial, and SNR
scalability layers; and combining and storing the encrypted coding
data of the temporal, spatial, and SNR scalability layers and the
generated metadata.
24. The method of claim 23, wherein the encrypting of the video
data of the coded temporal, spatial, and SNR scalability layers
comprises encrypting each of the coding data of the temporal,
spatial, and SNR scalability layers or any combination of the
temporal, spatial, and SNR scalability layers.
25. A method for protecting scalable video coding contents, the
method comprising: dividing input video data into at least one of
temporal, spatial, and SNR scalability layers; coding the input
video data of the at least one of the temporal, spatial, and SNR
scalability layers; grouping bit-streams for the input video data
of the coded temporal, spatial, and SNR scalability layers as a
combination of the at least one temporal, spatial, and SNR
scalability layers to form tiers; encrypting one or more of the
formed tiers; and generating encryption information for the
encrypted tiers as metadata.
26. The method of claim 25, further comprising combining the
encrypted tiers or original tiers and the metadata for tier
protection and storing the result as one file or as separate
data.
27. The method of claim 25, wherein the encrypting of one or more
of the formed tiers comprises either protecting all the tiers or
selectively encrypting bit-stream data corresponding to a specified
scalability combination in the tier.
28. A computer-readable recording medium having a program stored
therein for executing a method for protecting scalable video coding
contents claim 1.
29. A computer-readable recording medium having a program stored
therein for executing a method for protecting scalable video coding
contents according to claim 5.
30. A computer-readable recording medium having a program stored
therein for executing a method for protecting scalable video coding
contents according to claim 23.
31. A computer-readable recording medium having a program stored
therein for executing a method for protecting scalable video coding
contents according to claim 25.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method and apparatus for
protecting scalable video coding contents, and more particularly,
to a method and apparatus capable of reducing the computational
complexity of encryption and decryption by encrypting only data of
scalable video coding contents for each coding layer in terms of
temporal, spatial, and Signal-to-Noise Ratio (SNR) scalabilities,
to provide a service for protected scalable video coding contents,
the method and apparatus also capable of protecting contents by
generating and distributing an encryption key for encryption and
decryption depending on a class of a contents consumer.
[0003] 2. Discussion of Related Art
[0004] As is known, a conventional compressed video content
protection scheme involves packetizing video contents and
encrypting the resultant packets upon transmission to protect the
contents, or encrypting stored, compressed video contents to
protect them.
[0005] However, the protection scheme has a disadvantage of high
computational complexity in decrypting encrypted compressed video
contents. Also, the scheme encrypts all data of respective layers
in scalable video coding contents, increasing inefficient
computational complexity.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to a method and apparatus
for protecting scalable video coding contents that are capable of
reducing the computational complexity of encryption and decryption
by encrypting only data of scalable video coding contents for each
coding layer in terms of temporal, spatial, and SNR scalabilities
to provide a service for protected scalable video coding contents,
and capable of protecting contents by generating and distributing
an encryption key for encryption and decryption depending on a
class of a contents consumer.
[0007] An aspect of the present invention provides a method for
protecting scalable video contents in a scalable video coding
contents providing system that encrypts and provides scalable video
contents requested by a scalable video user terminal, the method
including: receiving the requested scalable video contents; storing
the received scalable video contents in a scalable video contents
archive and controlling to perform authentication and generate an
encryption key to be sent to the user; performing the
authentication and generating the encryption key; imaging a
scalable video in response to the request and coding the imaged
scalable video contents; encrypting the coded scalable video
contents using the generated encryption key; generating encryption
information metadata for the encrypted scalable video coding
contents; and transmitting the encrypted scalable video coding
contents and the generated encryption information metadata to the
scalable video user terminal via a network or a storage medium.
[0008] Another aspect of the present invention provides a method
for protecting scalable video coding contents in a scalable video
user terminal that decrypts and decodes encrypted scalable video
coding contents and encryption information metadata received from a
scalable video coding contents providing system, the method
including: parsing the received encryption information metadata to
obtain an encryption key and encryption information; decrypting the
received encrypted scalable video coding contents using the
encryption key and the encryption information; and decoding and
reproducing the decrypted scalable video contents.
[0009] Still another aspect of the present invention provides
scalable video coding contents providing system for protecting
scalable video contents requested by a scalable video user
terminal, the system including: a user contents request information
receiving unit for receiving the requested scalable video contents;
a scalable video contents service control unit for storing the
received scalable video contents in a scalable video contents
archive and controlling to perform authentication and generate an
encryption key to be sent to the user; a user authenticating and
encryption key control unit for performing the authentication and
generating the encryption key; an imaging unit for imaging a
scalable video in response to the request; a scalable video coding
unit for coding the imaged scalable video contents; a scalable
video coding data encryption unit for encrypting the coded scalable
video contents using the generated encryption key; an encryption
information metadata generation unit for generating encryption
information metadata for the encrypted scalable video coding
contents; and encrypted scalable video coding contents and
encryption information metadata transmission unit for transmitting
the encrypted scalable video coding contents and the generated
encryption information metadata to the scalable video user terminal
via a network.
[0010] Yet another aspect of the present invention provides a
scalable video user terminal for protecting encrypted scalable
video coding contents and encryption information metadata by
decrypting and decoding the same, the terminal including: an
encrypted scalable video metadata parsing unit for parsing received
encryption information metadata to obtain an encryption key and
encryption information; a scalable encrypted video decryption unit
for decrypting the received encrypted scalable video coding
contents using the encryption key and encryption information; a
scalable video decoding unit for decoding the decrypted scalable
video contents; and a scalable decoded video rendering unit for
rendering and reproducing the decoded scalable video contents.
[0011] Yet another aspect of the present invention provides an
apparatus for protecting scalable video coding contents, the
apparatus including: an input unit for dividing and inputting input
video data acquired in response to a request from a video user
terminal into at least one of temporal, spatial, and SNR
scalability layers; a coding unit for coding the input video data
of at least one of the temporal, spatial, and SNR scalability
layers; an encryption unit for encrypting video data of the coded
temporal, spatial, and SNR scalability layers; a generation unit
for generating metadata for the video data of the encrypted
temporal, spatial, and SNR scalability layers; and a storage unit
for combining and storing the encrypted coding data of the
temporal, spatial, and SNR scalability layers and the generated
metadata.
[0012] Yet another aspect of the present invention provides a
method for protecting scalable video coding contents, the method
including: dividing and inputting input video data acquired in
response to a request from a video user terminal into at least one
of temporal, spatial, and SNR scalability layers; coding the input
video data of the at least one of the temporal, spatial, and SNR
scalability layers; encrypting the video data of the coded
temporal, spatial, and SNR scalability layers; generating metadata
for the video data of the encrypted temporal, spatial, and SNR
scalability layers; and combining and storing the encrypted coding
data of the temporal, spatial, and SNR scalability layers and the
generated metadata.
[0013] Yet another aspect of the present invention provides a
method for protecting scalable video coding contents, the method
including: dividing input video data into at least one of temporal,
spatial, and SNR scalability layers; coding the input video data of
the at least one of the temporal, spatial, and SNR scalability
layers; grouping bit-streams for the input video data of the coded
temporal, spatial, and SNR scalability layers as a combination of
the at least one temporal, spatial, and SNR scalability layers to
form tiers; encrypting one or more of the formed tiers; and
generating encryption information for the encrypted tiers as
metadata. Meanwhile, the input video data may be input as one or
more layers rather than three scalability layers.
[0014] The method may further include combining the encrypted tiers
or original tiers and the metadata for tier protection and storing
the result as one file or as separate data. Meanwhile, the
encrypting of one or more of the formed tiers may include either
protecting all the tiers or selectively encrypting bit-stream data
corresponding to a specified scalability combination in the
tier.
[0015] Yet another aspect of the present invention provides a
computer-readable recording medium having a program stored therein
for executing a method for protecting scalable video coding
contents. That is, the method for protecting scalable video coding
contents according to the present invention may be implemented by a
computer code in a computer-readable recording medium. The
computer-readable recording medium includes any type of recording
device for storing data that can be read by a computer system.
[0016] For example, examples of the computer-readable recording
medium include a read-only memory (ROM), a random access memory
(RAM), a compact disk read-only memory (CD-ROM), a magnetic tape, a
hard disk, a floppy disk, a movable storage device, a nonvolatile
memory (e.g., flash memory), and an optical data storage device.
The recording medium may also be implemented by a transmission
medium, such as carrier waves (e.g., Internet-based
transmission).
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The above and other objects, features and advantages of the
present invention will become more apparent to those of ordinary
skill in the art by describing in detail preferred exemplary
embodiments thereof with reference to the attached drawings, in
which:
[0018] FIG. 1 illustrates temporally disassembled and assembled
scalable video frames according to the present invention;
[0019] FIG. 2 illustrates an MPEG-4 scalable video coding (AVC)
block;
[0020] FIG. 3 illustrates a temporal/spatial scalability structure
for scalable video coding contents protection according to the
present invention;
[0021] FIG. 4 illustrates a Fine Granular Scalability (FGS) block
of an apparatus for protecting MPEG-4 scalable video coding
contents according to the present invention;
[0022] FIG. 5 is a block diagram illustrating an apparatus for
protecting scalable video coding contents according to the present
invention;
[0023] FIG. 6 illustrates an example of a layered scalable
bit-stream representation structure of the present invention;
[0024] FIG. 7 illustrates a file format box structure for scalable
bit-stream protection according to the present invention; and
[0025] FIG. 8 illustrates a file format box structure for scalable
bit-stream protection according to the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0026] Hereinafter, exemplary embodiments of the present invention
will be described in detail. The present invention is not limited
to the embodiments disclosed below, but can be implemented in
various forms. The following embodiments are described to enable
those of ordinary skill in the art to embody and practice the
invention.
[0027] FIGS. 1a and 1b illustrate temporally disassembled and
assembled scalable video frames according to the present invention.
FIG. 1a illustrates a temporally disassembled scalable video frame
and FIG. 1b illustrates a temporally assembled scalable video
frame.
[0028] First, referring to FIG. 1a, successive video frames are
divided into respective frame (picture) groups. In each picture
group, a low-pass filtered picture and a high-pass filtered picture
each having a 1/2 temporal resolution form one layer through
temporal filtering. The layer is divided into a low-pass filtered
picture and a high-pass filtered picture each having a 1/2 temporal
resolution on a lower layer. In other words, the temporal
disassembly process is continued until only one low-pass filtered
picture remains on the lowest layer.
[0029] Next, referring to FIG. 1b, a process of temporally
assembling scalable video frames is the reverse of the disassembly
process, and includes obtaining a low-pass filtered picture on the
same layer from the low-pass filtered picture of the lowest layer
obtained in the disassembly process, using a high-pass filtered
picture of a next upper layer. This process is performed until
resolution of an original image is obtained.
[0030] In other words, when the temporally disassembled scalable
video contents are transmitted, the low-pass filtered picture of
the lowest layer is first transmitted and then high-pass filtered
pictures of next upper layers are transmitted in sequence. Here,
the low-pass filtered pictures of all upper layers can be protected
by encrypting only the lowest low-pass filtered picture for
scalable video protection. Encryption of high-pass filtered
pictures of the upper layer according to an allowed temporal
resolution can allow temporal resolution of only pictures of lower
layers.
[0031] FIG. 2 illustrates an MPEG-4 scalable video coding (AVC)
block. Spatial resolution of original image pictures is reduced
through down sampling or filtering, and the pictures having the
reduced spatial resolution are input to a coding block for a
corresponding layer. The lowest layer in which pictures having the
smallest spatial resolution are coded is coded by an MPEG-4 AVC or
H.264 video coding scheme, and input pictures on each upper layer
are coded using motion vectors, texture, a residual signal, and the
like, used for coding the lower layer. The coding structure is
called coarse granular scalability. Meanwhile, each coding layer
may be coded by fine granular scalability capable of performing
coding with image quality divided into sub-classes.
[0032] FIG. 3 illustrates a temporal/spatial scalability structure
for scalable video coding contents protection according to the
present invention.
[0033] Referring to FIG. 3, {circle around (0)} to {circle around
(4)} denote pictures of a lower layer n, and {circle around (5)} to
{circle around (9)} denote pictures of an upper layer n+1. Here,
the pictures of the lower layer n are coded through temporal
disassembly and the pictures of the upper layer n+1 are coded with
the same temporal disassembly structure as the pictures of the
lower layer n. Upon coding, the pictures of the upper layer n+1 are
coded using motion vectors, texture, a residual signal, and the
like, from the corresponding pictures of the lower layer n.
[0034] For example, picture {circle around (7)} of the upper layer
n+1 is coded using motion vectors, texture, a residual signal, and
the like, used upon coding picture {circle around (2)} of the lower
layer n, and using pictures {circle around (5)} and {circle around
(9)}. Accordingly, when pictures {circle around (0)} and {circle
around (4)} are encrypted for scalable video contents protection,
all of pictures {circle around (1)}, {circle around (2)}, and
{circle around (3)} and pictures {circle around (5)} to {circle
around (9)} cannot be reproduced without decrypting pictures
{circle around (0)} and {circle around (4)}. This is very effective
for scalable video contents protection.
[0035] FIG. 4 illustrates a Fine Granular Scalability (FGS) block
in an apparatus for protecting MPEG-4 scalable video coding
contents according to the present invention.
[0036] A base layer of the FGS codes an input image through a
converting, scaling, and quantizing process, and decodes the coded
image through a reverse process to obtain a residual signal with
the original image. An enhancement layer of the FGS receives the
residual signal from the base layer of the FGS, performs a
converting and scaling process and a finer quantization than that
of the base layer of the FGS on the residual signal, and
entropy-codes the result.
[0037] Meanwhile, a further residual signal is obtained from the
image decoded by the enhancement layer and the image decoded by the
base layer. The result is used only as an input of a next
enhancement layer. This process is continuously performed on a
desired FGS layer. In terms of FGS content protection, when the
residual signal obtained by the lower layer is encrypted, a
decoding process cannot be correctly performed in the next
enhancement layers without decrypting the residual signal.
[0038] The scalable video coding contents protection considering
all of the temporal, spatial, and SNR scalabilities in FIGS. 1, 2,
3 and 4 will be described with reference to FIG. 1a.
[0039] In FIG. 1a, a low-pass filtered picture L.sub.3 on the
lowest layer of the base layer is the most basic picture. When the
picture L.sub.3 has been encrypted, one entire group of pictures
(GoP) cannot be reproduced without successively decrypting the
picture L.sub.3. Since the group of pictures of the base layer
cannot be all decoded, pictures of upper layers cannot be all
decoded as well.
[0040] When, on the base layer, the L.sub.3 picture is not
encrypted and other H.sub.3 high-pass filtered pictures are
encrypted, only the L3 picture in one group of pictures can be
decoded. Accordingly, the picture L.sub.3 of the lowest layer even
in an enhancement layer corresponding to the picture of the lowest
layer L.sub.3 of the base layer can be decoded. When corresponding
pictures L.sub.3 of the enhancement layers are to be protected
while permitting decoding of only the picture L.sub.3 of the base
layer, only the L.sub.3 picture coding data of the enhancement
layer is protected, such that pictures L.sub.3 of upper enhancement
layers cannot be decoded without performing decryption.
[0041] Similarly, protection of only pictures above the picture
L.sub.2 needs only encrypt a high-pass filtered picture H.sub.2,
and protection of only pictures above the picture L.sub.1 needs
only encrypt high-pass filtered pictures H.sub.2.
[0042] A low-pass filtered picture L.sub.3 and high-pass filtered
pictures H.sub.3, H.sub.2 and H.sub.1 on the temporal resolution
layer of the base layer are encrypted using a different encryption
key, and disclosure of the encryption key is limited depending on
different user groups and business models, which allows the user
group to consume the same scalable video contents in a different
scalability level.
[0043] FIG. 5 is a block diagram of an apparatus for protecting
scalable video coding contents according to the present
invention.
[0044] A scalable video coding contents providing system 100
includes a camera 101 as a video acquiring apparatus, a video
acquisition block 102, a scalable video coding block 103, a
scalable video contents service control block 104, a user
authentication and encryption-key control block 105, a scalable
video coding data encryption block 106, an encryption information
metadata generation block 107, an encryption information metadata
archive 108, a scalable video contents archive 109, a contents
acquisition block 110, an encrypted scalable video coding contents
and encryption information metadata transmission block 111, and a
user contents request information receiving block 112.
[0045] A scalable video user terminal 200 may be a wired terminal
(e.g., a computer having a network access unit) or a wireless
terminal (e.g., a cellular phone, a Personal Communication System
(PCS), a Personal Digital Assistant (PDA), an IMT-2000, a PDA
phone, or a smart phone). The scalable video user terminal 200
includes an encrypted scalable video coding contents and encryption
information metadata receiving block 201, an encrypted scalable
video metadata parsing block 202, a scalable encrypted video
decryption block 203, a scalable video decoding block 204, a
scalable decoded video rendering block 205, a user interface block
206, and a scalable video request and response receiving block
207.
[0046] Operation of the apparatus for protecting scalable video
coding contents according to the present invention will be
described in greater detail.
[0047] Referring to FIG. 5, the user interface block 206 in the
scalable video user terminal 200 requests scalable video contents
from the scalable video coding contents providing system 100 via a
network 300.
[0048] The scalable video coding contents providing system 100
receives the scalable video contents requested by the user via the
user contents request information receiving block 112 and inputs
the same to the scalable video contents service control block
104.
[0049] The scalable video contents service control block 104
receives the scalable video contents, stores the scalable video
contents in the scalable video contents archive 109, controls the
user authentication and encryption key control block 105 to perform
authentication and generate an encryption key to be provided to the
user.
[0050] In this case, the camera 101 images a video to generate the
requested scalable video contents under control of the scalable
video contents service control block 104. The video acquisition
block 102 acquires the generated scalable video contents and
provides the same to the scalable video coding block 103.
[0051] The scalable video coding block 103 codes the provided
scalable video contents and provides the same to the scalable video
coding data encryption block 106.
[0052] The scalable video coding data encryption block 106 performs
user authentication on the coded scalable video contents, encrypts
the content using the encryption key from the encryption key
control block 105, and provides the encrypted content to the
encrypted scalable video coding contents and encryption information
metadata transmission block 111 and the encryption information
metadata generation block 107.
[0053] In this case, the encryption information metadata generation
block 107 generates encryption information metadata for the
encrypted scalable video coding contents provided from the scalable
video coding data encryption block 106, stores the encryption
information metadata in the encryption information metadata archive
108, and inputs the encryption information metadata to the
encrypted scalable video coding contents and encryption information
metadata transmission block 111.
[0054] The encrypted scalable video coding contents and encryption
information metadata transmission block 111 receives the encrypted
scalable video coding contents from the scalable video coding data
encryption block 106 and the generated encryption information
metadata from the encryption information metadata generation block
107, and sends the same to the scalable video user terminal 200 via
the network 300.
[0055] Meanwhile, referring to FIG. 5, the encrypted scalable video
coding contents and encryption information metadata receiving block
201 in the scalable video user terminal 200 receives the encrypted
scalable video coding contents and encryption information metadata
via the network 300. In this case, the encrypted scalable video
metadata parsing block 202 parses the encryption information
metadata to obtain the encryption key and related encryption
information and sends the same to the scalable encrypted video
decryption block 203
[0056] The scalable encrypted video decryption block 203 decrypts
the encrypted scalable video coding contents from the encrypted
scalable video coding contents and encryption information metadata
receiving block 201 using the encryption key and the related
encryption information from the encrypted scalable video metadata
parsing block 202, and provides the decrypted contents to the
scalable video decoding block 204.
[0057] The scalable video decoding block 204 decodes the decrypted
scalable video contents and provides the same to the scalable
decoded video rendering block 205.
[0058] The scalable decoded video rendering block 205 renders the
decoded scalable video contents and outputs the contents via the
user interface 206 so that an output unit (not shown) reproduces
the contents.
[0059] FIG. 6 illustrates an example of a layered scalable
bit-stream representation structure of the present invention. A
tier is a unit for tying one or more SVC bit-streams into one
group. As shown in FIG. 6, a base tier ties base layer bit-streams.
An example of a three-scalability level combination (a temporal
scalability level, a spatial scalability level, and a coarse SNR
scalability level), i.e., tier 1 (T0, S1, B0), (T1, S1, B0), (T1,
S0, B0)), tier 2 {(T0, S1, B0), (T2, S0, B0)}, tier 3 ((T0, S2,
B0), (T1, S2, B0), (T2, S2, B0)) is shown.
[0060] Here, when the base tier is protected (encrypted), Tier 1,
Tier 2, and Tier 3, which depend on the base tier, cannot be
recovered without decrypting the base tier, which protects all the
tiers. If tier 1 {(T1, S1, B0)} is protected (encrypted), tier 3
{(T1, S2, B0), (T2, S2, B0)} and tier 2 {(T0, S1, B0)} which depend
on tier 1 {(T1, S1, B0)} can be protected without being
encrypted.
[0061] FIG. 7 illustrates a file format box structure for scalable
bit-stream protection according to the present invention. The file
format structure of FIG. 7 includes a file type box (FTYP), a moov
box (MOOV), and an MDAT box (MDAT). The file type box (FTYP)
indicates file type (e.g., an SVC type) information, the moov box
(MOOV) includes video stream information (e.g., an SVC stream)
information, and the MDAT box (MDAT) is defined as a box for
storing actual data (e.g., an SVC stream). The moov box (MOOV)
recursively includes a track box (TRAK), a MDIA box (MDIA), and a
sample table box (STBL). The moov box (MOOV) has a Sample-to-Group
(SBGP) box for designating a sample group in the sample table box
(STBL), and a Sample Group Description (SGPD) box for recording
sample group information.
[0062] FIG. 8 illustrates a file format box structure, e.g., a
Sample Group Description (SGPD) box structure of a sample table box
(STBL) for scalable bit-stream protection according to the present
invention. Here, the structure includes a ProtectionSchemeInfoBox(
) data structure for tier protection. The ProtectionSchemeInfoBox(
) data structure is as follows:
TABLE-US-00001 Aligned(8) class ProtectionSchemeInfoBox(fmt)
extends Box (`sinf`) { OrigianlFormatBox(fmt) original_format; //
optional IPMPInfoBox IPMP_descriptors; // optional // IPMPInfoBox
is used for MPEG-4 IPMP/IPMPX // For SVC layed protection,
SchemeTypeBox and SchemeInfomationBox is used. SchemeTypeBox
scheme_type_box; // optional SchemeInfomationBox info; // optional
}
[0063] Meanwhile, SVCOperatingPointBox indicates a dependence
relationship between tiers by representing temporal, spatial, and
SNR scalability information using temporal_level, dependency_id,
and quality_level information in the respective tiers. A data
structure of SVCOperatingPointBox is as follows:
TABLE-US-00002 class SVCOperatingPointBox extends Box (`svop`) (
unsigned int(2) reserved = 0; unsigned int(6) simple_priority_id;
unsigned int(3) temporal_level; unsigned int(3) dependency_id;
unsigned int(2) quality_level; unsigned int(2)
progressive_refinement; unsigned int(2) discardable; unsigned
int(4) reserved = 0; }
[0064] Thus, the present invention allows for very effective
layered dependence protection of the scalable video bit-stream
using the layered dependence in the file format structure
illustrated in FIGS. 7 and 8.
[0065] According to the present invention, the computational
complexity of encryption and decryption can be reduced by
encrypting only data of scalable video coding contents for each
coding layer in terms of temporal, spatial, and SNR scalabilities,
to provide a service for protected scalable video coding contents.
And, contents can be protected by generating and distributing an
encryption key for encryption and decryption depending on a class
of a contents consumer. Thus, the encrypted compressed video
contents can be decrypted with reduced computational complexity,
and a conventional problem of increased inefficient computational
complexity caused by encrypting all the data of all layers of the
scalable video coding contents can be resolved.
[0066] While the invention has been shown and described with
reference to certain exemplary embodiments thereof, it will be
understood by those skilled in the art that various changes in form
and details may be made therein without departing from the spirit
and scope of the invention as defined by the appended claims.
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